foo.cc: In function 'int main()':
foo.cc:9:5: error: 'nowc' was not declared in this scope
  if(nowc==str.size()-1) {
     ^~~~
foo.cc:9:5: note: suggested alternative: 'now5'
  if(nowc==str.size()-1) {
     ^~~~
     now5
foo.cc:13:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(i=now5;i!=str.size();i++)
             ~^~~~~~~~~~~~
foo.cc:8:33: warning: unused variable 'j' [-Wunused-variable]
  int last5,now5=str.find('5'),i,j;
                                 ^

[Hydro](https://hydro.ac)提供评测服务